Axis-finder for a lens.



C. MILGROM & D. DUNN. AX-IS FINDER FOR A LENS. APPLICATION FILED AUG.2,1916- Patented July 3, 1917.

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CHARLES MILGROM AND DAVID DUNN, OF PHILADELPHIA, PENNSYLVANIA.

AXIS-FINDER FOR, A LENS.

Application filed August 2, 1916.

To all whom it may concern:

Be it known that we, CHARLES MILGROM and DAVID DUNN, both citizens of the United States, residing in the city and county of Philadelphia, State of Pennsylvania, have invented a new and useful Axis-Finder for a Lens, of which the following is aspecification. I

Our invention consists of an improvement in an axis finder for lenses, the same being of simple and inexpensive construction, and conveniently operative, as will be hereinafter described, the novel features of the same being pointed out in the claims.

The invention is satisfactorilyillustrated in the accompanying drawing, but the important instrumentalities thereof may be varied, and so it is to be understood that the invention is not limited to the specific details shown and described.

Figure 1 represents a perspective of an axis finder for a lens embodying our invention.

Fig. 2 represents a horizontal section of a portion thereof, on an enlarged scale on line 22' Figxl.

Fig. 3 represents a horizontal section of a portion thereof, on an enlarged scale on line 3-3 Fig. 1.

F'g. 4 represents a horizontal section of a portion thereof, on an enlarged scale on line 44 of Fig. 1.

F 5 represents a face view of one of the rings of the device on an enlarged scale. Fig. 6 represents a partial side elevation and vertical section of a modification.

Similar numerals of reference indicate corresponding parts in the figures.

Referring to the drawings.

1 designates a pair of radially moving arms which are pivotally mounted on one end by the thumb screw 2, on ears 3, which extend from the supporting plate or base 4, the latter being attachable to a wall, bench, or a table, as desired, it being noticed that the arms may be raised and lowered on said screws 2, and held in desired position by tightening said screws, whereby they are clamped to said ears.

On the outer end of said arms 1 are fitted the bosses 5 with which are connected the annulus or ring 6 which forms the carrier for a protractor 7, the latter being composed of a late of transparent material having on the ace thereof lines of graduations of de- Specifieation of Letters Patent.

Patented July 3, 1917.

Serial No. 112,660.

grees, the peripheral rim of said annulus having connected with it the resilient clip 8 on Whose free end is a piece or head 21 of suitable material which is adapted to sup port on the protractor a lens, pressing the latter against the center of the face of the protractor. Again, the clip 8 has a free end, and: sides diverging from said end to the periphery of the carrier to which the clip is secured, providing abroad base for connection of the clip with the carrier, said clip otherwise being of somewhat light construction.

9 designates a plate or disk which is intermediate 'of the protractor and the supporting plate 4 and having on the face the cross lines 10, saiddisk being secured to the ring 11 on whose periphery are the bosses 12 which are' received on the arms 1, thus supporting the ring and consequently the disk, it being noticed that the protractor and the cross lined disk are movable on the arms 1, and so may be moved to and from each other, and so adjusted relatively to each other for purposes requiring the same.

Within the bosses 5 and interposed between the same and the adjacent portions of the arms 1 are the springs 13 which hold said bosses frictionally on said arms, a feature of importance in moving the ring 6 on saidarms for nice adjustment of the protractor thereon. Then when the adjustment is accomplished, the bosses 5 are held firmly on the arms by suitable set screws 5 which are fitted to the bosses and adapted to tighten against the adjacent portions of the arms.

Within the bosses 12 and interposed between the same and the adjacentportions of the arms 1 are the springs 14: which hold said bossesfrictionally on said arms, a feature of importance in moving the ring 11 on said arms for nice adjustment of the disk 10 thereon.

The springs 14 have their forward ends fitted in ofiset recesses 15 in-the openings of the bosses 12, the opposite ends of the springs having thereon. the deflected lips 16 which engage the opposite ends of the bosses, and so prevent displacement of the springs, all as shown in Figs. 2 and 3.

The springs 13 are formed and held in place 7similarly to the springs 14 by the li s 1 Ihe operation of finding the axis of a lens in our device is somewhat; similartd that in devices of a similar class heretofore known, that is to say, when a lens is applied to the protractor as shown in Fig. 1, whether the same is a complete lens, as shown at 18, or only a piece of a lens, and the protractor is raised to the required height, When the eye is directed through the lens or the piece thereof and the portion of the protractor back of the same, the portions of the lines of graduations of the pro'tractor being seen through the lens afiiected by the latter, the disk 9 with its cross lines 10 being also visi'- ble through the lens and protractor. Then the protractor is turned until one of the lines of the graduations of the protractor seen through thelens and protractor registers exactly with one of the cross lines 10 of the disk 9. Then the number or graduation of said line as read off is the pattern line or axis for the lens to be ground.

If desired, as shown in Fig. 6, the plate or disk 9 may be secured to a table, or bench 19, and the arms 1 made movable therein so as to adjust the protract'or to and from the cross lines 10 thereon and adapt it to'be set to the height of the eye. To provide for this, the ring 11 has openings 20 formed therein, shown in dotted lines, Fig. 5, and in full lines Fig. 6, to receive the screws shown in the latter by which said ring is secured to said table or bench 19.

Attention is drawn to the fact that the p'rotractor is rotatable on the ring '6 to the extent of a circle in either direction to the right or left, and so it may quickly find the registration of the desired graduation line thereon with that on the disk 9 by rotating the protractor in either direction until sai'd registration is accomplished.

Having thus described our invention what Copies of this patent may be obtained-for weclailh as new and desire to secure by Letters Patent, is

1. In an axis finder for a lens, parallel arms, a ringsupported thereon, a-protractor carried by said ring, means on the ring adapted to hold a lens on said protractor, bosses on said ring, the same having openings therethrough adapted to freely receive said arms, said openings having in their peripheral portions offset recesses, springs adapted to occupysaid recesses and to here'- tained therein and engage frictionally the sides of said arms, and set screws on said boisses adapted to engage positively said si es.

2, In an axis finder for a lens, parallel arms, a ring, a disk with lines thereon can ried by said ring, bosses on said ring having therethrou'gh openings adapted to freely receive said arms, said openings having: in their frictional portions offset recesses and springs adapted to occupy said recesses and to be retained therein and engage frictionally the sidesof said arms.

3. In an" axis finder for a lens, arms, a protractor and a disk,the latter having thereon cross lines, both disk and protractoi' being slidihgly fitted on said armspsaid disk being rearward of said protractor, a base having slotted ears thereon, the swinging ends of said arms having their adjacent ends in the slot'sof said ears, and screws'forniing the axes of said arms, said screws being passed through the ends of said arms and the side members of said ears and serving also" to clamp said members and ends to each other.

CHARLES MILGROM'. DAVID DUNN. Witnesses:

JOHN A; IViEniiRsHErM, N. Brissmeiin.

five cents each, by addressing the Commissioner of Patents. Washington, D; C. 

